Imaging apparatus and imaging method which perform focus adjustment while performing live-view display

ABSTRACT

An imaging apparatus performing live-view display by generating image data using an exposure parameter calculated from a brightness value in a photometric area for the live-view display which is different from a photometric area for focus adjustment when not performing the focus adjustment, the imaging apparatus comprising: a first calculating section for calculating a first brightness value in the photometric area for the live-view display; a second calculating section for calculating a second brightness value in the photometric area for focus adjustment; a comparison section for determining whether or not a brightness difference between the first brightness value and the second brightness value is within a predetermined range; and, an imaging section for obtaining image data by performing exposure using the first brightness value when the brightness difference between the first brightness value and the second brightness value is within the predetermined range.

RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 14/253,024 (referred to as “the '024 application”and incorporated herein by reference), filed on Apr. 15, 2014, titled“IMAGING APPARATUS AND IMAGING METHOD” and listing Satoru ITO as theinventor, the '024 application claiming benefit of Japanese ApplicationNo. 2013-085772 filed in Japan on Apr. 16, 2013, the contents of whichare incorporated by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus and an imagingmethod which perform focus adjustment while performing live-viewdisplay.

2. Description of Related Art

There has been known a camera which performs exposure by setting anexposure parameter (exposure time, aperture value, etc.) calculatedbased on brightness in a predetermined photometric area of a subject,when performing normal live-view display without performing focusadjustment (hereinafter, such exposure is called “LVAE”), and whichperforms the exposure for obtaining image data for the focus adjustmentby selecting a photometric area for the focus adjustment (hereinafter,called “AFAE”) and also uses the image data obtained based on this AFAEin parallel for the live-view display, when performing the live-viewdisplay together with focus adjustment. However, since generally aphotometric range for the case of performing the focus adjustment isfrequently narrower than the photometric range for the case ofperforming the normal live-view display, even for image data on the samesubject area, between the image data for the focus adjustment and theimage data for the normal live-view display, not only the level of theimage data is different but also the brightness distribution mode of theimage is frequently different because of saturation of the image data.Accordingly, the image quality of the live-view display changes betweenbefore and after the focus adjustment and a user feels uncomfortable.

Japanese Patent Laid-Open No. 2010-68046 (hereinafter, called “PatentLiterature 1”) solves a problem as described above by correcting theimage data for the focus adjustment so as to cause the levels of theimage data to become close to each other between the focus adjustmentand the normal live-view display.

SUMMARY OF THE INVENTION

In Patent Literature 1, the level of the captured image data isdifferent between before and after release operation, even for the samesubject part. For example, when, although the image data obtained byperforming LVAE for some subject area does not reach a saturation level,the image data obtained by performing AFAE for the same subject areareaches the saturation level, it is not possible to correct the imagedata obtained by AFAE into the image data having the same image qualityas that of the image data obtained by LVAE. Accordingly, in such a case,even when the image data is corrected, the image quality of thelive-view display still changes between before and after the focusadjustment, and thus the user feels uncomfortable.

The present invention has been achieved in view of such a situation, andaims to provide an imaging apparatus and an imaging method which performthe live-view display by generating the image data using the exposureparameter calculated from the brightness value of the photometric areafor the live-view display which is different from the photometric areafor the focus adjustment when not performing the focus adjustment, andalso can perform the focus adjustment in a high accuracy whileperforming the live-view display in a preferable image quality despitewhether the focus adjustment is being performed or not when performingthe live-view display also during the focus adjustment.

An imaging apparatus according to the present invention is an imagingapparatus performing live-view display by generating image data using anexposure parameter calculated from a brightness value in a photometricarea for the live-view display which is different from the photometricarea for focus adjustment when not performing the focus adjustment, andperforming the live-view display also when performing the focusadjustment, and includes: a focus adjustment brightness valuecalculation section comparing a first brightness value in thephotometric area for the live-view display with a second brightnessvalue in the photometric area for the focus adjustment, correcting thefirst brightness value according to a comparison result, and calculatinga brightness value for obtaining the image data for the focusadjustment; an imaging section obtaining the image data by performingexposure using the brightness value calculated by the focus adjustmentbrightness value calculation section; a focus adjustment sectionperforming the focus adjustment using the image data obtained by theimaging section; and a display section performing the live-view displayusing the image data obtained by the imaging section.

An imaging method according to the present invention is an imagingmethod performing live-view display by generating image data using anexposure parameter calculated from a brightness value in a photometricarea for the live-view display which is different from the photometricarea for focus adjustment when not performing the focus adjustment, andperforming the live-view display also when performing the focusadjustment, and includes the steps of: comparing a first brightnessvalue in the photometric area for the live-view display with a secondbrightness value in the photometric area for the focus adjustment,correcting the first brightness value according to a comparison result,and calculating a brightness value for obtaining the image data for thefocus adjustment; obtaining the image data by performing exposure usingthe calculated brightness value; performing the focus adjustment usingthe obtained image data; and performing the live-view display using theobtained image data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram mainly showing an electrical configuration ofa camera according to Embodiments 1 to 3.

FIG. 2 is a flowchart showing an operation flow of camera controlaccording to Embodiment 1 to 3.

FIG. 3 is a subroutine showing a flow of LVAE processing of a cameraaccording to Embodiments 1 to 3.

FIG. 4 is a subroutine showing a flow of LVAE-AFAE exposure differencesuppression processing in a camera according to Embodiment 1.

FIG. 5 is a subroutine showing a flow of AFAE processing of a cameraaccording to Embodiments 1 to 3.

FIGS. 6A to 6C show an example of photometric areas and a focus area inthe whole imaging area according to Embodiments 1 to 3, in which FIG. 6Ais a diagram showing the focus area, FIG. 6B is a diagram showing thephotometric area for LVAE, and FIG. 6C is a diagram showing thephotometric area including the focus area.

FIG. 7 is a graph showing a relationship between a difference of thebrightness of a focus adjustment photometric area from the brightness ofa live-view display photometric area (delta_bv) and a correction valuefor correcting the brightness value of the live-view display photometricarea to calculate a brightness value for performing focus adjustment(bv_revise), in Embodiment 1.

FIG. 8 is a graph showing a relationship between a difference of thebrightness of a focus adjustment photometric area from the brightness ofa live-view display photometric area (delta_bv) and a correction valuecorrecting the brightness value of the live-view display photometricarea to calculate a brightness value for performing focus adjustment(bv_revise), in Embodiment 2.

FIG. 9 is a graph showing a relationship between a difference of thebrightness of a focus adjustment photometric area from the brightness ofa live-view display photometric area (delta_bv) and a correction valuecorrecting the brightness value of the live-view display photometricarea to calculate a brightness value for performing focus adjustment(bv_revise), in Embodiment 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

In the following, preferred Embodiment 1 will be explained by the use ofa camera to which the present invention is applied. Note that, in thefollowing explanation, explanation or detailed explanation will beomitted for the same operation and control technique as those of atypical imaging apparatus.

A camera according to Embodiment 1 is a digital camera, includes animaging element 105, converts a subject image into image data in thisimaging element 105, and displays the subject image on a display sectionin real time (hereinafter, called “live-view display”) according to thisconverted image data. In photographing, a photographer selects an areawhere a subject is to be focused (hereinafter, called “focus area”) anddetermines composition by observing the live-view display. When arelease button included in an operation section 114 is half-pressed(hereinafter, called “1st release”), the focus of a photographic lens100 is adjusted, and, when the release button is further pressed fully(hereinafter, called “2nd release”), photographing is performed. Theimage data obtained in the photographing is recorded into a memory 111after having been subjected to predetermined image processing in animage processing circuit 110.

FIG. 1 is a block diagram mainly showing an electrical configuration ofthe camera according to Embodiment 1. The camera according to Embodiment1, when broadly divided, includes a lens unit 10, and a camera body 20.The lens unit 10 includes the photographic lens 100, a diaphragm 101, alens/diaphragm drive motor 102 for the driving thereof, a motor drivecircuit 103, and a lens-side CPU 104. Further, the camera body 20includes the imaging element 105, an imaging-control/signal-processingcircuit 106, a camera-side CPU 107, an AF (Auto Focus) estimation valuecalculation circuit 108, an AE (Auto Exposure) estimation valuecalculation circuit 109, the image processing circuit 110, the memory111, a display circuit 112, a display section 113, the operation section114, and a recording medium 115.

The photographic lens 100 is configured with plural optical lenses forforming a subject image, and is a single focus lens or a zoom lens. Thediaphragm 101 is disposed on an optical axis of the photographic lens100 around an exit pupil of the photographic lens 100, and adjustsincident light intensity and focal depth. The diaphragm 101 and thephotographic lens 100 are controlled by the camera-side CPU 107, thelens-side CPU 104, the motor drive circuit 103, and the motor 102, andfocus adjustment and aperture adjustment are realized. Here, thelens-side CPU 104 interprets a control command received from thecamera-side CPU 107 to be described below, and controls the lens 100 andthe diaphragm 101.

The imaging element 105 is disposed on the optical axis of thephotographic lens 100, and performs the imaging of a subject imageformed by the photographic lens 100. This imaging element 105 isconfigured with pixels which include photodiodes and are arranged in atwo-dimensional matrix, and stores electric charge according to receivedlight intensity. Electric charge storage control, image signal read-outcontrol, and the like of the imaging element 105 are performed by theimaging-control/signal-processing circuit 106 connected to the output ofthe imaging element 105. The image data read out from this imagingelement 105 is output to the camera-side CPU 107, the AF estimationvalue calculation circuit 108, the AE estimation value calculationcircuit 109, the image processing circuit 110, and the memory 111.

The AF estimation value calculation circuit 108 detects a focusing stateof a subject using a high-frequency component of the image data outputfrom the imaging element 105. This AF estimation value calculationcircuit 108 is used also as a focus adjustment section. The AEestimation value calculation circuit 109 calculates a brightness valuewhen the focus adjustment image data is obtained, by correcting abrightness value of the photometric area when the live-view image datais obtained, and calculates an exposure time (Tv) and an aperture value(Av) for obtaining appropriate exposure in the live-view display and inthe focus adjustment. This AE estimation value calculation circuit 109is used also as a focus adjustment brightness value calculation section.The image processing circuit 110 performs various kinds of imageprocessing such as synchronization processing, gradation conversionprocessing, white balance adjustment, edge processing, for the imagedata readout from the imaging element 105. The image data subjected tothe image processing is recorded into the recording medium 115 mountedon the camera body 20 detachably.

When the user operates the operation section 114 connected to thecamera-side CPU 107, the AF estimation value calculation circuit 108,the AE estimation value calculation circuit 109, the image processingcircuit 110, and the memory 111 are controlled by the camera-side CPU107, and the focus adjustment, the exposure control, the imageprocessing, and the like are performed as basic operations of thecamera. At this time, in operation accompanying the control of the lensand the diaphragm such as AF and AE, the camera-side CPU 107 transmits acontrol command to the lens-side CPU 104 according to a control programstored in the memory 111, using output values of the AF estimation valuecalculation circuit 108 and the AE estimation value calculation circuit109. Further, the camera-side CPU 107 displays a live-view imageexpressed by the display image data generated in the image processingcircuit 110, on the display section 113 via the display circuit 112.

Next, a specific operation flow of the present invention using the abovedescribed electrical configuration will be explained with reference toflowcharts in FIG. 2 to FIG. 5. Note that, in the explanation of thefollowing operation, each of the operations is performed by thecamera-side CPU 107 as far as not mentioned otherwise in particular.

FIG. 2 is a flowchart showing an operation flow of the camera controlaccording to Embodiment 1. First, in step S21, the camera-side CPU 107obtains By for LVAE (Brightness value) (variable name: lvae_bv) which isa brightness value of a photometric area for the normal live-viewdisplay without the focus adjustment. This lvae_bv is calculated in theAE estimation value calculation circuit 109 by so-called apexcalculation based on an average level of the image data of the LVAEphotometric area in the image data obtained by the imaging of theimaging element 105.

At this time, a scene as shown in FIG. 6A is assumed. In an exampleshown in FIG. 6A, a house Sub1 (part provided with hatching) on theright side of a screen has a low brightness because of a shadow area,and a background Sub2 including mountains has a high brightness becauseof the sunshine. The main subject is a person and a focus area F1 is setat a face part.

FIG. 6B shows the LVAE photometric area M-LVAE in the live-view display,and this area is set across a wide range as shown in FIG. 6B. Since mostof the LVAE photometric area M-LVAE has a high brightness in the sceneshown in FIG. 6B, lvae_bv has a large value. LVAE processing isperformed using this lvae_bv in step S22. This LVAE processing performsappropriate exposure control for live-view by calculating and setting anexposure condition using lvae_bv.

Next, the LVAE processing in step S22 will be explained in detail withreference to a subroutine in FIG. 3. This LVAE processing is executed bya cooperative operation of the AE estimation value calculation circuit109 and the camera-side CPU 107. Step S31 determines Av, Tv, and Sv forLVAE (respective variable names: lvae_av, lvae_tv, and lvae_sv) whichare derived from a program chart (not shown in the drawing) usinglvae_bv obtained in step S21.

In step S32, a diaphragm control instruction to cause the diaphragm 101to provide the value of lvae_av is transmitted from the camera-side CPU107 to the lens-side CPU 104. Similarly, in step S33, an imaging elementcontrol instruction to cause the imaging element 105 to have an exposuretime and a sensitivity of lvae_tv and lvae_sv, respectively, istransmitted from the camera-side CPU 107 to theimaging-control/signal-processing circuit 106. The exposure suitable forLVAE is performed by these instructions. After the LVAE processing isfinished, the flow returns from the subroutine of FIG. 3.

Next, in step S23 of FIG. 2, it is determined whether the 1st releaseoperation has been performed or not. When it is determined that the 1strelease operation has been performed, the flow goes to processing afterthe 1st release operation in step S24.

Generally, the photometric area for AFAE is different from thephotometric area for LVAE. For example, compared with the LVAEphotometric area M-LVAE shown in FIG. 6B, the AFAE photometric areaM-AFAE which is the photometric area around the focus area shown in FIG.6C is different in a position and an area size of the photometric area.Accordingly, when the LVAE processing for performing the live-viewdisplay is executed using By (variable name: afae_bv) which is abrightness value for AFAE, the image quality of the live-view display isdegraded when AF processing is performed. In particular, the imagequality of the live-view display changes between before and after the1st release operation and a user feels uncomfortable. Accordingly, inEmbodiment 1, when it is determined that the 1st release operation hasbeen performed, LVAE-AFAE exposure difference suppression processing isperformed as described in the following, in step S24.

Next, with reference to FIG. 4, a flow of the LVAE-AFAE exposuredifference suppression processing will be explained in detail. Here,this LVAE-AFAE exposure difference suppression processing is executed bya cooperative operation of the AE estimation value calculation circuit109 as a brightness value correction section and the camera-side CPU107.

In step S41, the camera-side CPU 107 obtains By (afarea_bv) which is abrightness value in the AF photometric area around the focus area. Next,in step S42, a difference between afarea_bv and lvae_bv(afarea_bv−lvae_bv) is calculated to give delta_bv. Next, in step S43,it is determined whether or not track_limit_low≦delta_bv≦track_limit_hiholds. That is, it is determined whether or not delta_bv is included ina tracking region (upper limit variable: track_limit_hi and lower limitvariable: track_limit_low).

This tracking region is a range of delta_bv in which an AF accuracy canbe secured even if lvae_bv is used as By (variable name: afae_bv) whichis a brightness value for AFAE. When delta_bv is included in thistracking region, after afae_bv of By for AFAE has been replaced bylvae_bv in step S44, the flow returns from the LVAE-AFAE exposuredifference suppression processing subroutine.

That is, for the case that delta_bv is included in the tracking region,AFAE after the LVAE-AFAE exposure difference suppression processingbecomes the same as LVAE. Accordingly, in the case that delta_bv isincluded in the tracking area, the image quality of the live-viewdisplay does not change between before and after the 1st releaseoperation is performed. Further, the AF accuracy is also guaranteed.

On the other side, in the case that delta_bv is not included in thetracking region, if afae_bv=lvae_bv, there is a possibility that the AFaccuracy cannot be secured. Accordingly, in the case that delta_bv isnot included in the tracking region, a value of lvae_bv to which a Bycorrection value (variable name: bv_revise) is added as a trackingregion excess amount, is used for afae_bv.

First, in step S45, it is determined whether or nottrack_limit_low>delta_bv holds. For the case of track_limit_low>delta_bvas the result of this determination, next, in step S46, when the Bycorrection value is expressed by bv_revise, it is determined thatbv_revise=delta_bv−track_limit_low. On the other side, when it is notdetermined in step S45 that track_limit_low>delta_bv, it is determinedin step S47 that bv_revise=delta_bv−track_limit_hi.

After processing of step S46 or step S47 is finished, next, in step S48,the By correction value calculated in step S46 or step S47 is added toBy for LVAE to give afae_bv. After the calculation ofafae_bv=lvae_bv+bv_revise is performed in step S48, the flow returnsfrom the subroutine of the LVAE-AFAE exposure difference suppressionprocessing.

In this manner, the LVAE-AFAE exposure difference suppression processing(processing of a focus adjustment brightness value calculation section)in the present embodiment calculates the brightness value (afae_bv) forobtaining image data for the focus adjustment by adding the correctionvalue (bv_revise) to a first brightness value (lvae_bv) of thephotometric area for the live-view display, and sets the correctionvalue to zero when the brightness difference between the firstbrightness value and a second brightness value of the photometric areafor the focus adjustment is not larger than a predetermined value andincreases the correction value as the brightness difference becomeslarger when the brightness difference is larger than the predeterminedvalue.

FIG. 7 is a graph showing a relationship between the above describeddelta_bv and bv_revise. In FIG. 7, the horizontal axis shows thedifference value (delta_bv) between the first brightness value (lvae_bv)for the live-view display and the second brightness value of thephotometric area for the focus adjustment, and the vertical axis showsthe correction value (bv_revise). As apparent from FIG. 7, when thedifference value (delta_bv) between the first brightness value (lvae_bv)of the photometric area M-LVAE for the live-view display and the secondbrightness value of the photometric area for the focus adjustment isincluded in the tracking region (track_limit_low to track_limit_hi), thecorrection value (bv_revise) is zero, and, when the difference value(delta_bv) between the first brightness value (lvae_bv) and the secondbrightness value is not included in the tracking region (smaller thantrack_limit_low or larger than track_limit_hi), the correction value isdetermined according to the brightness difference.

In this manner, according to the present embodiment, it is possible toprovide an imaging apparatus and an imaging method which can perform thefocus adjustment in a high accuracy while performing the live-viewdisplay in a preferable image quality despite whether the focusadjustment is being performed or not.

After the LVAE-AFAE exposure difference suppression processing isfinished, next, AFAE processing is performed in step S25 of FIG. 2.Next, this AFAE processing will be explained in detail with reference toFIG. 5.

First, in step S51, Av, Tv and Sv for AFAE (respective variable names:afae_av, afae_tv, and afae_sv) derived from a program chart common toLVAE and AFAE are determined using By for AFAE (variable name: afae_bv)obtained in step S24. The above processing is executed by the AEestimation value calculation circuit 109 and the camera-side CPU 107.Next, in step S52, the camera-side CPU 107 transmits the diaphragmcontrol instruction corresponding to afae_av to the lens-side CPU 104.Next, in step S53, the camera-side CPU 107 transmits the imaging elementcontrol instructions corresponding to afae_tv and afae sv to theimaging-control/signal-processing circuit 106.

After the AFAE processing is finished, next, instep S26 of FIG. 2, it isdetermined whether the 2nd release operation has been performed or not.When the 2nd release operation has not been performed, the flow returnsto step S23 and the above described processing is performed repeatedly.When it is determined in step S26 that the 2nd release operation hasbeen performed, next, in step S27, the exposure control is performedusing the exposure parameters Av, Tv, and Sv calculated in the abovedescribed LVAE processing. This exposure control is executed under acooperative operation of the camera-side CPU 107, theimaging-control/signal-processing circuit 106, the diaphragm 101, theimaging element 105 and the like. After the exposure control isfinished, next, the image data is read out from the imaging element 105and a predetermined image processing is performed in theimaging-control/signal-processing circuit 106, and the image processingcircuit 110. Next, in step S30, the image data is recorded into therecording medium 115.

Embodiment 2

Embodiment 2 is different from Embodiment 1 only in the LVAE-AFAEexposure difference suppression processing of step S24 in FIG. 2. Theother configuration and processing are the same as those in Embodiment1, and only the different point will be explained in the followingexplanation.

FIG. 8 shows a relationship between the difference of the brightness ofthe focus adjustment photometric area from the brightness of thelive-view display photometric area (delta_bv), and the correction valuefor correcting the brightness value of the live-view display photometricarea to calculate the brightness value for performing the focusadjustment (bv_revise), in the present embodiment.

In the present embodiment, bv_revise is increased as the absolute valueof delta_bv becomes larger when delta_bv is included in the range fromthe lower limit value track_limit_low to the upper limit valuetrack_limit_hi. That is, lvae_bv is corrected and afae_bv is calculatedso as to cause the difference between lvae_bv and afae_bv to beincreased as the absolute value of delta_bv becomes larger. On the otherside, when delta_bv is not included in the range from the lower limitvalue track_limit_low to the upper limit value track_limit_hi, as shownin FIG. 8, it is configured such that the straight line bv_revise of thevertical axis is inclined to delta_bv of the horizontal axis by 45degrees. This means that bv_revise has a value obtained by subtracting aconstant value from delta_bv. The above processing is executed by acooperative operation of the AE estimation value calculation circuit 109as the brightness value correction section and the camera-side CPU 107.

In the present embodiment, when delta_bv is included in the range fromthe lower limit value track_limit_low to the upper limit valuetrack_limit_hi, bv_revise is increased as the absolute value of delta_bvbecomes larger. Accordingly, compared with Embodiment 1, it is possibleto adjust the balance between the accuracy of the focus adjustment andthe image quality of the live-view display more delicately.

Embodiment 3

Embodiment 3 is different from Embodiment 1 only in the LVAE-AFAEexposure difference suppression processing of step S24 in FIG. 2. Theother configuration and processing are the same as those of Embodiment1, and only the different point will be explained in the followingexplanation.

FIG. 9 shows a relationship between the difference of the brightness ofthe focus adjustment photometric area from the brightness of thelive-view display photometric area (delta_bv), and the correction valuefor correcting the brightness value of the live-view display photometricarea to calculate the brightness value for performing the focusadjustment (bv_revise), in the present embodiment.

In the present embodiment, when delta_bv is included in the range fromthe lower limit value track_limit_low to the upper limit valuetrack_limit_hi, as the absolute value of delta_bv becomes larger,lvae_bv is corrected and afae_bv is calculated so as to cause thedifference between lvae_bv and afae_bv to be increased. On the otherside, when delta_bv is not included in the range from the lower limitvalue track_limit_low to the upper limit value track_limit_hi, the slopeof a straight line showing a relationship between delta_bv and bv_reviseis increased slightly from the slope of the straight line when delta_bvis included in the range from from track_limit_low to track_limit_hi.This means that lvae_bv is corrected and afae_bv is calculated so as tocause the difference between lvae_bv and afae_bv to be always increasedas the absolute value of delta_bv becomes larger, in the presentembodiment. The above processing is executed by a cooperative operationof the AE estimation value calculation circuit 109 as the brightnessvalue correction section and the camera-side CPU 107.

In this manner, in the LVAE-AFAE exposure difference suppressionprocessing (processing of focus adjustment brightness value calculationsection) in the present embodiment, the focus adjustment brightnessvalue calculation section calculates the brightness value (afae_bv) forobtaining the image data for the focus adjustment by adding thecorrection value (bv_revise) to the first brightness value (lvae_bv) ofthe live-view display photometric area, and increases the correctionvalue as the brightness difference between the above described firstbrightness value (afae_bv) and the second brightness value of the focusadjustment photometric area (afarea_bv) becomes larger.

According to the present embodiment, compared with Embodiments 1 and 2,it becomes possible to adjust the balance between the accuracy of thefocus adjustment and the image quality of the live-view display moredelicately.

The present invention is not limited to the above described embodiments,and can be also realized by modification of the constituents in a rangewithout departing from the gist thereof in the stage of implementation.For example, while, in Embodiment 1, the live-view display is performedbased on the image obtained using LVAE before the release operation andthe focus adjustment and also the live-view display are performed basedon the image data obtained using AFAE after the release operation, therelease operation is not necessarily essential. That is, the case thatthe AF control is performed while the live-view display is beingperformed is also included in the scope of the present invention.Further, by an appropriate combination of the plural constituentsdisclosed in the above described embodiments, various inventions can beformed. Further, the constituents across the different embodiments maybe combined appropriately. In this manner, various modifications andapplications are possible in a range without departing from the gist ofthe invention.

What is claimed is:
 1. An imaging apparatus performing live-view displayby generating image data using an exposure parameter calculated from abrightness value in a photometric area for the live-view display whichis different from a photometric area for focus adjustment when notperforming the focus adjustment, and performing the live-view displayalso when performing the focus adjustment, the imaging apparatuscomprising: a first calculating section for calculating a firstbrightness value in the photometric area for the live-view display; asecond calculating section for calculating a second brightness value inthe photometric area for focus adjustment; a comparison section fordetermining whether or not a brightness difference between the firstbrightness value and the second brightness value is within apredetermined range; an imaging section for obtaining image data byperforming exposure using the first brightness value when the brightnessdifference between the first brightness value and the second brightnessvalue is within the predetermined range; a focus adjustment sectionperforming the focus adjustment using the image data obtained by theimaging section; and a display section performing the live-view displayusing the image data obtained by the imaging section.
 2. The imagingapparatus according to claim 1, wherein the predetermined rangecorresponds to a range capable of securing accuracy of the focusadjustment even though performing exposure using the first brightnessvalue.
 3. An imaging method performing live-view display by generatingimage data using an exposure parameter calculated from a brightnessvalue in a photometric area for the live-view display which is differentfrom a photometric area for focus adjustment when not performing thefocus adjustment, and performing the live-view display also whenperforming the focus adjustment, the imaging method comprising the stepsof: a first step of calculating a first brightness value in aphotometric area for the live-view display; a second step of calculatinga second brightness value in the photometric area for focus adjustment;a third step of comparing a brightness difference between the firstbrightness value and the second brightness value with a specified value;a fourth step of obtaining image data by performing exposure using thefirst brightness value responsive to a determination that the brightnessdifference between the first brightness value and the second brightnessvalue is within a predetermined range; a fifth step of performing thefocus adjustment using the image data obtained in the fourth step; and asixth step of performing the focus adjustment using the image dataobtained in the fifth step.
 4. The imaging method of claim 3 wherein thepredetermined range corresponds to a range capable of securing accuracyof the focus adjustment even though performing exposure using the firstbrightness value.